What gauge steel should be used on these frames in a cut out/weld in scenario? I have a small 2”x4” section in the rear that is not perforated but has rust from a mount that had rust under it.
I have read 11 gauge, 1/8, 3/16 but nothing definitive.
What would be the best for a small rectangular section like this?

thanks all

 

The stock frame steel is 4mm, or 0.158 inch, or 5/32 inch. I've heard of people using 1/8" mild steel before with good results.